You can set your App Store preferences to “Download newly available updates in the background”. If you're using OS X El Capitan v10.11.5 or later, these updates include major new macOS versions, like macOS Sierra. Your Mac then notifies you when the updates are ready to install.

If your enterprise is concerned with data usage or network bandwidth, you should turn off background downloads.

Use a configuration profile

You can use a configuration profile to prevent background downloads. In the profile, set the AutomaticDownload key to False in the com.apple.SoftwareUpdate domain. Learn more about creating configuration profiles.

Use a Terminal command

If you’re a system administrator and need to make this update on multiple computers, run the following command in Terminal as an admin user: